Eval¶

Hardware¶

Display: WSH-12561; 37,32x31,8; 200x200Pixel; eval board funktioniert
Akku: 31063 (Garmin Fenix 3) 300mAh; 300 mAh; 31,6 x 24,8 x 4,3; Reichelt

MCU¶

Pixel-data is 5KB ((200*200)/8); need bigger MCU; but the STM32L433CCU6 i have is too much

STM32L433CCU6: Too much
STM32L151C6U6A waers eigentlich. USB, 128KB Flash, 32KB SRAM, EEPROM 32KB Flash, 10KB RAM, hat USB
STM32L051C8T6; no USB
STM32L053C8T6; 11,60Euro, whatt?

STM32L151C6U6A hab ich schon hier. "DS:Link
STM32L151CB gibts auch noch, wenn auch teure 12.15Euro. Biedes UFQPFN-48.
STM32L1xxx6(8/B) does not support USB bootloader.

Check the binary size. Along with USB.

• Fonts, USB, Terminal, Debug, LUT: 29616
• Fonts, USB, Terminal, RelWIthDebug, LUT: 22884

Alphabet: 22 Zeichen * 8 Bytes= 176 Bytes. Display-Content 5000 Bytes.
32KByte koennten reichen. Versions on Display optional.
4KByte EEPROM fuer Settings.

FLASH¶

nice, compact
GD25Q16EEIGR; 16Mb; USON8

Power¶

Lade-Chip: https://www.mouser.de/datasheet/2/268/MCP73871_Data_Sheet_DS20002090F-2932254.pdf
VCI wants 3V3. VDDIO may be less but is not specified. Reference schematics connects VDDIO directly to VCI.
Start with 3V3.

"ad_mcp73871" is getting manufactured. Lets see how it behaves on V_OUT.

V_OUT is ok. But there is no discharge protection. Additional chip needed like:

• AP9211; normal 3.0μA (Typ.), 4.5μA (Max.); Power-Down 0.1μA

Chip

Open points¶

MCU: 1.65 V to 3.6 V power supply, would need LDO. Would need this self-holding-mosfet chain. Would need seperate battery for RTC. MCU has not VBAT.
There are low IQ LDOs. "((48*1000)/1,6) / 24 / 356" = 3,511236 years.
LDO
ADC can also be connected directly. Stop working at 3V. There is no "Low-Battery" signal on the ordered revision of the MCP73871.

LDO mit shutdown/enable: AP2127

Protection¶

• AP9211SA-AL-HAC-7 TME
  Link
  2x NMOS, 20V, 2A

Tests¶

• Run with Battery < 3V;
  • Is Shutdown of MCP73871 working No, need additional part; AP9211SA-AL-HAC-7, AP9101CAK6-ANTRG1.
  • Is Low-Battery-Detection implemented on STM32 working?

Actions¶

• ad_mcp73871
• ad_mcp73871_2; Ohne das Switch-gedoens. Mit ADC Ausgang. Wiederstaende muessen ja noch nicht passen.

BOM¶

• GD25Q16EEIGR
• STM32L151C6U6A; 48Pins; 32KB Flash; UFQFPN
• MCP73871 (Charger)
• AP9211SA-AL-HAC-7 (Protector)
• 31063 (Garmin Fenix 3)

Next try¶

• eInk-Schaltung plus STNS01 plus buzzer/LEDs/button
  • https://www.st.com/resource/en/datasheet/stns01.pdf
  • Shutdown is not usable because input power has to be connected again.
  • max. 150mA
  • Ibat= max 10μA; ((300000 / 10) / 24) / 364 = approx. 3,4340659 ano
• Ganz normale WKUP-Schaltung vom MM
• ueber Mosfets anschalten wenn USB gesteckt wird, zweiter WKUP?
• 5 items
• LEDs: HB, User, Chrg, VUSB
• Kein seperater LDO fuer Display; auch programmieren ohne USB-Verbindung soll moeglich sein
• BTMS on ADC
• Flash fuer Symbole oder weitere Schriften.
• eInk-eval mit 3V testen

LDO-LED¶

• With 120Ohm device lives around 2 days. Just remove it.

Battery<-Life-Time¶

• STNS01 draws 6-10 μA when I_LDO=0; in theory 3,4 years
• With the 2 dark LEDS permanent on: ((300000 / 6010) / 24) = 2 days; plausible!
• STM32 draws 0.28 μA Standby mode (3 wakeup pins) (DS)
• 1.11 μA Standby mode + RTC (DS)
• Resistor directly on V_LDO-Output of STNS01 is bad because the VDD would change depending how many LEDs are turned on
• Put ADC-measure-GND to an GPIO so it wont draw current when not measured/off
• 10µA+1.11µA; assume 20µA;
• Spannungsteiler; 26µA